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Mamenchisaurus
' ''Mamenchisaurus ' (/mɑːˈmʌntʃiˈsɔrəs/ mah-MUN-chi-SAWR-əs,1 or spelling pronunciation /məˌmɛntʃiˈsɔrəs/) is a sauropod dinosaur genus including several species, known for their remarkably long necks2 which made up half the total body length.3 It is known from numerous species which ranged in time from 160 to 145 million years ago, from the Oxfordian to Tithonian ages of the late Jurassic Period of China. It may include the species ''Mamenchisaurus sinocanadorum. Discovery Mamenchisaurus was first discovered in 1952 on the construction site of the Yitang Highway in Sichuan, China. The partial skeleton fossil was then studied, and named Mamenchisaurus constructus in 1954, by the renowned Chinese paleontologist Professor C. C. Young. The type specimen had an incomplete neck with 14 vertebra preserved and none of these were complete. M. constructus has been estimated around 13 m (43 ft) and 15 m (49 ft)in length.45 In 1972, a second species of Mamenchisaurus was discovered (M. hochuanensis) with a neck that reached up to 9.3 m (31 ft) in length.6 This species had a complete neck preserved which contained 19 vertebrae.7 In 1994, Sauroposeidon was discovered in the United States, with a neck estimated to be between 10.5 and 11.5 meters (34.5–37.5 feet) long, though its neck did not exceed that of the previously known Supersaurus, with a neck reaching 13–14 meters (42.5–46 feet).8 In 1993, M. sinocanadorum was described based on a skull and the first four cervical vertebrae; this species possessed the longest cervical rib of any described sauropod dinosaur, measuring 4.1 m (13.5 ft). This is longer than the longest Sauroposeidon cervical rib, which measures 3.42 m (11.2 ft).9 Additional remains attributed to this species but not yet formally described comprise almost the entire skeleton. Mounted specimens of M. sinocanadorum measure 35 metres (115 ft) in length with a 18 metres (59 ft) long neck.4 In 2001, another M. hochuanensis specimen was described. It had skull, pectoral girdle and forelimb material preserved, all of which were missing from the holotype. It was also found with four fused tail vertebra, which have expanded neural arches and taller neural spines, that belong at the tip of the tail. It’s thought that these could be a weapon, such as a tail club, or a sensory organ. Other Chinese sauropods, Shunosaurus and Omeisaurus, are also known to have had ’tail clubs’ but they differ in shape to that of M. hochuanensis. Naming Mamenchisaurus means 'Mamenchi lizard', from the Chinese Pinyin mǎ (马 'horse') and mén (门 'gate'), while chi is a transliteration of xī (溪 'stream' or 'brook'), combined with the suffix -saurus (from Greek sauros meaning 'lizard'). It was intended to name the reptile after the place where its fossil was first found — a construction site next to the Mǎmíngxī (马鸣溪) Ferry Crossing by the Jinsha River (金沙江, the westernmost major headwater stream of the Yangtze River), near Yibin (宜宾) in Sichuan Province of China. However, due to an accentual mix-up by Young, the location name Mǎmíngxī (马鸣溪 'horse-neighing brook') was mistaken as Mǎménxī (马门溪 'horse-gate brook').12 The fact that the first Mamenchisaurus fossil was found as the result of construction work led to Young's naming the type species as Mamenchisaurus constructus. Description Category:Jurassic dinosaurs Category:Sauropods Category:Dinosaurs of Asia Category:Article stubs